That's a good book. Project focused and practical. From my limited experience I think it is possible to write simple, dumb Rust, still get a N times performanc

That's a good book. Project focused and practical. From my limited experience I think it is possible to write simple, dumb Rust, still get a N times performance benefit using N times less resources compared the languages you listed at the cost of being more verbose. There's a learning curve to understanding concepts like lifetimes and so on. But diving deeper there arise many problems. There are just a ton of hyper specific and nuanced types and traits in Rust, and that's just the std lib. Reading Rust is also quite difficult because it takes time to navigate the types and abstractions. Also dependency trees seem to be deep in OS projects. It's a powerful, great language, but I would say the learning curve and the subtleties can _easily_ be underestimated, because there is an initial AHA moment when lifetimes, traits, closures, async etc. start to click. But the devil is in the details. But I think the need/want for safe, fast languages with good security defaults is on a steady rise, especially in web development. Clients (laymen) start to notice and praise good performance and robustness more than they did 10y in my experience, so it's definitely worth it to take a look at languages at Rust.